Advertising and other information is often temporarily presented on large sheets which are placed on billboards, truck panels and the like. One form of such sheet material is tensioned vinyl sheet. Such sheet may be printed upon and surrounded by a more rigid plastic border which is RF (radio frequency) welded to the sheet. The border typically includes a large bead, circular in cross section, which operates as a tenon in association with a C-shaped mortise associated with a mounting frame.
Mounting frames may take on a plurality of configurations. Of value is the ability to tension the sheet and to maintain it in a tensioned and wrinkle-free state. Mechanisms have been used which first lock the sheet in place and then apply tension through off-center bolts and the like.
The present invention is directed to a mounting for a sheet having a tenon and mortise element about at least a portion of the periphery of the sheet. The mounting includes two or more elongate frame members which are parallel and displaced from one another. At least one of the elongate frame members includes an engagement surface facing away from the other elongate frame member. An elongate retainer is associated with each of the elongate frame members that has an engagement surface. The elongate retainer has an interlocking surface which can be positioned in interlocking engagement with an engagement surface. An elongate retainer tenon and mortise element on the elongate retainer engages the sheet tenon and mortise element to hold the sheet.
In a first separate aspect of the present invention, the elongate frame member that has an engagement surface includes a frame rail surface which also faces away from the other elongate frame member. A retainer rail surface on the retainer faces away from the frame rail surface. These rail surfaces allow tensioning of a sheet through compression toward one another.
In a second separate aspect of the present invention, at least one of the elongate frame members has mutually parallel multiple engagement surfaces. The interlocking surface can then be in interlocking engagement with any of the engagement surfaces. This allows accommodation of different sheet sizes.
In a third separate aspect of the present invention, the one or more engagement surfaces are each located on the side of an elongate rib. The one or more ribs extend outwardly from the frame member and are angled away from the opposed elongate frame member. The interlocking surface on the elongate retainer may also be placed on the side of an elongate flange to interlock with an engagement surface.
In a fourth separate aspect of the present invention, any of the foregoing separate aspects may further include a second set of elongate frame members such that the two sets form a rectangular frame for retaining a sheet on all four sides.
In a fifth separate aspect of the present invention, any of the foregoing separate aspects may further include each set of the elongate frame members being identical, with one or more engagement surfaces and corresponding identical elongate retainers with interlocking surfaces.
In a sixth separate aspect of the present invention, any of the foregoing separate aspects may be combined to complement the mounting for a sheet.
Accordingly, it is an object of the present invention to provide an improved sheet mounting. Other and further objects and advantages will appear hereinafter.